DE102018104401B3 - Hydraulic camshaft adjuster and method for its locking - Google Patents

Abstract

The invention relates to a hydraulic camshaft adjuster (1) for variably adjusting the timing of gas exchange valves of an internal combustion engine, comprising a stator (2) and a rotor (3) rotatable relative to the stator (2), wherein the stator (2) protrudes radially inwards Webs (4) are formed and wherein on the rotor (3) radially outwardly projecting wings (5) are formed. Between the stator (2) and the rotor (3) a plurality of hydraulic working spaces (6) are formed, which are each divided by a wing (5) of the rotor (3) into a first working chamber and a second working chamber. In this case, in the rotor (3) has two locking elements (11, 12) for temporary, reversibly releasable fixation of the rotor (3) relative to the stator (2) used in a central position. It is provided that the first locking element (11) and the second locking element (12) in a common locking link (10) are lockable. The invention further relates to a method for locking the rotor (3) in such a hydraulic camshaft adjuster (1).

Description

The invention relates to a hydraulic camshaft adjuster and a method for locking a rotor of a hydraulic camshaft adjuster according to the preamble of the independent claims.

Hydraulic phaser are used in internal combustion engines to adjust the valve timing of the intake and exhaust valves to a corresponding load state of the internal combustion engine and thus to increase its efficiency. Hydraulic camshaft adjusters are known from the prior art, which operate on the vane principle. In this case, the camshaft adjuster includes a stator and a rotor rotatable relative to the stator, wherein between the stator and the rotor, a working space is formed, which is divided by a wing of the rotor into two working chambers. By a corresponding hydraulic pressurization of the working chambers, the position of the rotor relative to the stator can be changed and thus the timing of the valves can be adjusted. In this case, the rotor is usually adjustable between a late position and an early position, which are defined by corresponding stops on the stator. Further, hydraulic camshaft adjusters are known in which the rotor can be mechanically locked in a center position between the two stops. In this case, hydraulic camshaft adjusters are known in which such a central locking is realized by two locking pins, which can engage in two locking cams. However, a disadvantage of such a solution is that both two locking slots as well as two hydraulic supply channels have to be formed on the rotor in order to pressurize the respective locking slot for hydraulic unlocking, which leads to high production costs and correspondingly high production costs.

From the US 2005/0 016 481 A1 a hydraulic camshaft adjuster is known in which two locking elements can engage in a common locking link. In this case, two spring-loaded locking elements are provided on the stator of the hydraulic camshaft adjuster, which engage in a formed on a radially outer surface of the rotor locking slot and thus can lock the rotor relative to the stator.

From the DE 102 17 062 A1 a hydraulic camshaft adjuster is known with a locking mechanism, wherein the locking element is designed as a stepped locking pin, which can engage in a locking link. In this case, the locking pin is arranged in the rotor and can engage in the axial direction in a provided on a cover of the hydraulic camshaft adjuster locking link.

The US 2010/0 175 650 A1 shows a camshaft adjuster with a locking link in the output element, engage in the two plate-shaped locking elements.

The US 2009/0 250 028 A1 shows with 9A a camshaft adjuster with a stepped locking link in a locking lid, in which a stepped locking pin engages.

The DE 10 2013 224 862 A1 shows a camshaft adjusting device with a connectable to a crankshaft of an internal combustion engine stator, and a rotatably mounted relative to the stator, connectable to a camshaft rotor, and a locking device for locking the rotor relative to the stator with a statorfesten locking link and at least one lockable in the locking link rotor-fixed locking pin wherein the locking link is arranged in a statorfesten, on the rotor laterally adjacent, at least two-part lid, and the two parts of the lid are fastened to each other in different angles of rotation, wherein the locking link is formed by at least one provided in a first part of the lid recess and a projection engaging in the recess is provided on a second part of the lid.

The object of the invention is to reduce the complexity and thus the production costs in a hydraulic camshaft adjuster with two locking elements.

The object is achieved by a hydraulic camshaft adjuster for variable adjustment of the timing of gas exchange valves of an internal combustion engine, with a stator and a rotor rotatable relative to the stator, wherein on the stator radially inwardly projecting webs are formed and wherein on the rotor radially outwardly projecting wings are formed. Between the stator and the rotor a plurality of hydraulic working spaces are formed, which are each divided by a wing of the rotor into a first working chamber and a second working chamber. In this case, two locking elements are used for locking the rotor relative to the stator in a central position in the rotor. It is envisaged that the first locking element and the second locking element can be locked in a common locking link. The proposed solution is compared to the known from the prior art solution a locking linkage saved, which can be used to produce the locking link simpler tools. In addition, less material must be removed, which reduces material wear and reduces processing time. Thus, the manufacturing costs for the locking linkage are reduced. Further, on the rotor, a pressure medium supply for a locking link, hereinafter also referred to as C-channel, omitted, which also reduce the manufacturing and tooling costs for the rotor.

The features listed in the dependent claims advantageous refinements and improvements of the independent claim specified hydraulic camshaft adjuster are possible.

In a preferred embodiment of the invention, it is provided that the locking link is designed as a stepped locking link, wherein the locking link has at least one base, a middle stage and a plateau, wherein the middle stage between the base and the plateau is arranged or formed. In this case, despite a common locking link the same number of steps for the lock as shown in a camshaft adjuster with two locking latches. According to the multiple use of the locking stages in the locking link is thereby implemented so that the two locking elements are arranged in the rotor very close to each other, so that a locking element can use the locking stages and stops of the other locking element in the locking link with an adjustment.

According to an advantageous embodiment of the hydraulic camshaft adjuster is provided that both the first locking element and the second locking element abut the bottom of the locking link, when the rotor is locked in a central position. As a result, a stable and functionally reliable locking of the rotor in the center position is possible because the locking elements only stand out from the ground when the locking link is acted upon by a corresponding hydraulic control with pressure. The control is preferably carried out via a pressure medium pump and a central valve of the hydraulic camshaft adjuster and a C-channel, which connects the central valve with the locking link.

In an advantageous embodiment of the invention, it is provided that at the middle stage a first stop surface for the locking elements in the direction "early" and a second stop surface in the direction "late" are formed. The middle stage is made wider than the bottom of the locking link. As a result, manufacturing technology can easily and inexpensively realize a staircase form, on which the locking elements can rest in a downward direction in a rotation in the center position until the locking elements have reached the bottom of the locking link.

In a preferred embodiment of the invention it is provided that the locking link is formed or arranged in a locking cover of the hydraulic camshaft adjuster, which limits the stator and the rotor in the axial direction. A locking link in a cover can be compared to a locking link in the stator or rotor manufacturing technology simple and inexpensive. This can be done in particular by means of a forming process or a cutting process, in particular a milling process. Alternatively, it is possible to form the locking link by means of inserts which are inserted into a groove of the locking cover, in particular pressed.

According to a preferred embodiment of the invention, it is provided that the locking elements are designed as stepped locking elements, in particular as stepped locking pins. By means of stepped locking elements, both additional steps as well as additional functions can be realized. In this case, the locking pins in each case in two different stages with the locking link come into operative connection, namely once in a system of the end face of the locking element and once by the rest of the locking pin on the stage.

It is preferably provided that the stepped locking element has a cylindrical base body with a diameter D ₁ and a preferably coaxial with the cylindrical base body formed projection having a diameter D ₂ having, wherein the diameter D ₁ of the cylindrical body is greater than the diameter D ₂ of the projection. Such locking pins can be easily and inexpensively produced as turned parts or in a combination of a deep drawing process and a subsequent turning process. As an alternative to a cylindrical pin, the stepped locking element can also be embodied in other shapes, for example as rectangular plates.

In an advantageous embodiment of the hydraulic camshaft adjuster is provided that the stepped locking elements at the transition from the cylindrical body to Projection a circumferential bearing surface is formed. By a circumferential projection can be formed in a simple manner, an additional locking level, which can be trained with the described locking link five instead of only three locking stages. In this case, the stepped locking element can rest with the projection on the plateau (1st stage), with the circumferential projection resting on the plateau (2nd stage), with the projection resting on the middle stage (3rd stage), with the circumferential projection rest on the middle step (4th step) or rest on the ground with the projection (5th step). As a result, smaller rotations with lower forces and / or lower torques can be used to turn the rotor stepwise to the center position.

It is particularly preferred if the height of the middle stage of the locking link and / or the height of the ground is greater than the height of the projection on the stepped locking element is / are. This ensures that sufficient space is available for a support of the stepped locking element on the circumferential projection.

According to the invention, a method is proposed for locking a rotor of a hydraulic camshaft adjuster according to the invention, wherein the locking elements successively penetrate into the locking slot upon rotation of the rotor from an adjustment position to the central position, whereby rotation of the rotor in the direction of the center position is possible and counteracts rotation of the rotor the rotation is locked in the middle position. It can be with two locking elements and only a common locking link for the two locking elements represent a locking process, which allows the advantages of the known locking process with two locking scenes with lower manufacturing costs.

• 1 einen erfindungsgemäßen hydraulischen Nockenwellenversteller in einer Schnittdarstellung;
• 2 ein Ausführungsbeispiel für eine Verriegelungskulisse eines erfindungsgemäßen hydraulischen Nockenwellenverstellers, wobei eine sukzessive Verdrehung in die Mittenposition dargestellt ist; und
• 3 ein weiteres Ausführungsbeispiel für eine Verriegelungskulisse eines erfindungsgemäßen hydraulischen Nockenwellenverstellers, bei der eine sukzessive Drehung des Rotors aus einer Verstellposition in die Mittenposition dargestellt ist.

The invention is explained below with reference to preferred embodiments with reference to the accompanying figures (Fig.). Identical components or components with the same function are identified by the same reference numerals. Showing:

• 1 a hydraulic camshaft adjuster according to the invention in a sectional view;
• 2 an embodiment of a locking link of a hydraulic camshaft adjuster according to the invention, wherein a successive rotation is shown in the center position; and
• 3 a further embodiment of a locking link of a hydraulic camshaft adjuster according to the invention, in which a successive rotation of the rotor from an adjustment position is shown in the center position.

1 shows a hydraulic camshaft adjuster 1 according to the vane principle with a stator 2 and one relative to the stator 2 rotatable rotor 3 , Here is the rotor 3 rotatable about an axis of rotation in the stator 2 stored. The stator 2 has several bars 4 on, which in the radial direction of a cylindrical body in the direction of a central axis of the hydraulic camshaft adjuster 1 run. Between the rotor 3 and the stator 2 are workrooms 6 formed by radially from a main body of the rotor 3 protruding wings 5 in each case a first working chamber and a second working chamber are divided. At the stator 2 is a drive toothing 9 formed, with which the stator 2 is driven by a crankshaft of an internal combustion engine via a drive means, in particular a timing chain or a toothed belt. The stator 2 is closed at its axial end surfaces in each case by a lid. It is in one of the cover a locking link 10 trained or arranged. The lid with the locking link 10 is also referred to below as a locking lid 13 designated. The locking lid 13 can be executed both one-piece and multi-part. Opposite are in 2 and 3 each two-part versions of the locking lid 13 . 28 . 29 shown. Alternatively, the locking link 10 also in the axial direction between a cover of the hydraulic camshaft adjuster 1 and the stator 2 be arranged. In the rotor 3 are two locking elements 11 . 12 arranged, which via springs in each case in a recess of the rotor 3 are stored. Furthermore, oil supply channels are formed on the rotor, with which the working chambers and / or the locking link 10 can be controlled hydraulically with a pressure medium, in particular with an oil. The rotor 3 has a central opening into which a central valve, not shown for reasons of clarity, can be used to supply the pressure medium to the working chambers and / or the locking mechanism 10 . 11 . 12 driving.

In 2 is a first embodiment of a locking process of a hydraulic camshaft adjuster according to the invention 1 with two locking elements in the rotor 3 and a common locking link 10 for the two locking elements 11 . 12 shown. The illustrated locking link 10 includes a first latch cover 28 and a second locking lid 29 , In the illustrated starting position is the rotor 3 of the hydraulic camshaft adjuster 1 adjusted in the direction of "late". Should the rotor 3 Now be rotated from this adjustment position in the center position and locked there, a successive locking process. In the initial situation I is the rotor 3 so far from the center position in the direction of "late" twisted that both the first locking element 11 as well as the second locking element 12 on the plateau 19 the locking link 10 issue. Will the center lock function of the hydraulic camshaft adjuster 1 activated, then the rotor 3 rotated by the alternating moments with the camshaft in the direction of the center position. In this case, the first locking element decreases 11 in an adjustment step II in the locking frame 10 and lies on a heel of the middle stage 20 on. By the stop 25 in the direction of "late" turning back counter to the desired adjustment by the first locking pin 11 blocked. Will the rotor 3 rotated by the alternating torques of the camshaft further in the direction of the center position, the first locking element decreases 11 in an adjustment step III to the bottom 21 the locking link 10 while the second locking element 12 continue on the plateau 19 the locking link 10 rests. In this case, a rotation against the desired adjustment in the direction of the center position is locked by the fact that the first locking element 11 on a stop surface 23 which is the reason 21 bounded in the lateral direction. In a further adjustment step IV the second locking element sinks 12 to the middle level 20 the locking link 10 while the first locking element 11 in a middle position at the bottom 21 the locking link 10 is turned. The blocking effect against the desired adjustment results in this adjustment step IV by the abutment of the second locking element 12 at the stop 25 on the middle stage 20 the locking link 10 , In a final adjustment step V, the second locking element also sinks 12 to the bottom 21 the locking link 10 from. This is the rotor 3 locked in this position, since by the concerns of the first locking element 11 at the stop surface 22 and by the abutment of the second locking element 12 at the stop surface 23 both a rotation in the direction of "early" and a rotation in the direction of "late" is locked. To the rotor 3 To unlock, the locking link can 10 , especially the reason 21 the locking link 10 , hydraulically pressurized, causing the locking elements 11 . 12 against the force of the springs in the rotor 3 be inserted and thus a rotation of the rotor 3 release. Similarly, an adjustment of the rotor from an early position to the center position, wherein at such an adjustment, the second locking element 12 before the first locking element 11 in the locking frame 10 dive or first the reason 21 the locking link 10 reached.

In 3 is another embodiment of a locking process of a rotor 3 in a hydraulic camshaft adjuster according to the invention 1 shown. The locking mechanism 10 is in two parts with a first locking lid 28 and a second locking lid 29 executed, but may also be made in one piece or comprise more than two components. In a starting position VI is the rotor 3 adjusted in the direction of "late". The starting position in 3 essentially corresponds to the adjustment step III in 2 , In principle, it is also possible in this embodiment that the rotor 3 so far moved towards "late" is that both locking elements 11 . 12 on the plateau 19 the locking link 10 rest. The locking elements 11 . 12 are in this embodiment as stepped locking pins 14 executed, wherein the stepped locking pins 14 a cylindrical body 15 . 17 with a first diameter D ₁ and a respective coaxial with the cylindrical base body 15 . 17 trained lead 16 . 18 each having a diameter D ₂ having. Here is the diameter D ₁ of the cylindrical body 15 . 17 larger than the diameter of the respective projection 16 . 18 , so that in the transition region between the cylindrical body 15 . 17 and the lead 16 . 18 a circumferential bearing surface 26 . 27 results. In the starting position VI is the lead 16 of the first locking element 11 on the ground 21 the locking link 10 on while the projection 18 of the second locking element 12 on the plateau 19 rests. In the starting position shown is the rotor 3 freely rotatable in both directions of adjustment, ie a rotation is not locked or inhibited in this position. By rotating in the direction of the center position of the projection decreases 18 of the second locking element 12 in an adjustment step VII in the locking frame 10 a, so that the second locking element 12 with its surrounding bearing surface 27 resting on the plateau. By the concern of the projection 18 at the stop 25 at the middle stage 20 a rotation is locked against the desired adjustment in the direction of the center position. In the adjustment step VIII the second locking element sinks 12 further into the locking slot 10 one, so the lead 18 on the middle stage 20 rests while the first locking element 11 at the bottom 21 the locking link 10 in the direction of the stop surface 22 is moved. In a further adjustment step IX lies the circumferential bearing surface 27 of the second locking element 12 on the middle stage 20 on while the projection 18 in the direction of the ground 21 over the middle stage 20 protrudes. In a final adjustment step X lie both projections 16 . 18 on the ground 21 the locking link 10 on, wherein a rotation of the rotor by the stops 22 and 23 Is blocked. Thus, the rotor 3 locked in the center position and secured against unwanted twisting.

In summary, it can be stated that in a hydraulic camshaft adjuster according to the invention 1 a lock of the two locking elements 11 . 12 in a common locking frame 10 is possible. Thus, the manufacturing costs for the locking lid 13 as well as for the rotor 3 be lowered, as well as only a C-channel for pressure medium supply of the locking link 10 is necessary and thus a C-channel on the rotor 3 can be saved.

LIST OF REFERENCE NUMBERS

1

hydraulic camshaft adjuster

2

stator

3

rotor

4

web

5

wing

6

working space

7

-

8th

-

9

driving teeth

10

locking link

11

first locking element

12

second locking element

13

locking cover

14

stepped locking element

15

Basic body (of the first locking element)

16

Projection (of the first locking element)

17

Basic body (of the second locking element)

18

Projection (the second locking element)

19

Plateau of the locking gate

20

middle level of the locking link

21

Reason for the locking mechanism

22

Stop surface (in the direction of "early")

23

Stop surface (towards "late")

24

Stop surface (in the direction of "early")

25

Stop surface (towards "late")

26

Bearing surface (on the first locking element)

27

Bearing surface (on the second locking element)

28

first locking cover

29

second locking lid

D ₁

Diameter of the cylindrical body

D ₂

Diameter of the projection

H

Height of the projection

T ₁

Height of the middle stage

T ₂

Height of the ground

Claims (9)

Hydraulic camshaft adjuster (1) for variably adjusting the timing of gas exchange valves of an internal combustion engine, comprising - a stator (2) and a rotatable relative to the stator (2) rotor (3), -, on the stator (2) radially inwardly projecting webs (4) are formed, wherein, - on the rotor (3) radially outwardly projecting wings (5) are formed, wherein, - between the stator (2) and the rotor (3) a plurality of hydraulic working spaces (6) are formed, which are each divided by a wing (5) of the rotor (3) into a first working chamber and a second working chamber, and wherein - in the rotor (3) has two locking elements (11, 12) for locking the rotor (3) relative to the stator (2) are inserted in a central position, characterized in that - the first locking element (11) and the second locking element (12) in a common locking link (10) are lockable, wherein - the first locking element (11) or the second locking element (12) depending on the adjustment direction of the rotor (3) the stop surfaces (22, 23, 24, 25) share. Hydraulic camshaft adjuster (1) to Claim 1 , characterized in that - the locking link (10) is designed as a stepped locking link, wherein the locking link (10) has at least one base (21), a middle step (20) and a plateau (19), wherein - the middle step ( 20) between the base (21) and the plateau (19) is formed. Hydraulic camshaft adjuster (1) to Claim 2 , characterized in that - both the first locking element (11) and the second locking element (12) abut the base (21) of the locking link (10), when the rotor (3) is locked in a center position. Hydraulic camshaft adjuster (1) according to one of Claims 2 or 3 , characterized in that - at the middle stage (20) a stop surface (24) in the direction of "early" and a stop surface (25) in the direction of "late" is formed. Hydraulic camshaft adjuster (1) according to one of Claims 1 to 4 , characterized in that - the locking link (10) in a locking cover (13) of the hydraulic camshaft adjuster (1) is formed which limits the stator (2) and the rotor (3) in the axial direction. Hydraulic camshaft adjuster (1) according to one of Claims 1 to 5 , characterized in that - the locking elements (11, 12) as stepped locking elements (14) are formed. Hydraulic camshaft adjuster (1) to Claim 6 , characterized in that - the stepped locking element (14) has a cylindrical base body (15, 17) with a diameter D ₁ and a coaxial with the cylindrical base body (15, 17) formed projection (16, 18) with a diameter D ₂ wherein - the diameter D _{1 of} the cylindrical base body (15, 17) is greater than the diameter D _{2 of} the projection (16, 18). Hydraulic camshaft adjuster (1) to Claim 2 and Claim 7 , characterized in that - the heights (T ₁ , T ₂ ) of the middle step (20) and the bottom (21) are greater than the height (H) of the projection (16, 18). Method for locking a rotor of a hydraulic camshaft adjuster (1) according to one of Claims 1 to 8th , characterized in that - the locking elements (11, 12) upon rotation of the rotor (3) from an adjustment position in the center position successively penetrate into the locking link (10), whereby a rotation of the rotor (3) in the direction of the center position possible and a rotation of the rotor (3) is locked against the rotation in the center position.

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